236
R. Tesser et al.
The second solution is related to the development of new ‘compliant’ coating
technology, addresses the need for energy conservation, balances cost against necessary performance and provides compliance with environmental regulations [229].
In this case, four types of application can be possible:
• Waterborne coatings: coatings that utilize water as the major carrier liquid. The
resins commonly used need to be high hydrophilic, i.e. acrylics, alkyds, polyesters,
epoxies, polyurethanes and vinyls with common crosslinkers being melamines,
aziridines, carbodiimides and glycidyl compounds.
• Radiation curable coatings: combinations of unsaturated monofunctional and
multi-functional acrylated monomers and acrylated oligomers, characterized by
the presence of epoxy, polyester or polyurethane backbone.
• High solids coatings: incrementing the amount (>60%vol.) of solids in a conventional solvent-borne paint, it is possible to reduce the VOC content of a coating
formulation.
• Powder coatings: two types of powder coatings, thermoplastic and thermoset. The
firsts are resins melting and flowing at elevated temperatures; the seconds provide
similar melting and flow properties (75–85 °C) while changing their chemical
properties upon curing (140–200 °C).
Among the classical resins used in formations, different kinds of chemicals can be
used: i.e., acrylic, alkyd and polyesters, amino, epoxy resins and polyurethanes. Vegetable oils can be used as raw materials in producing most of the mentioned classes,
with the advantage of starting from a renewable resource, thus obtaining environmentally friendly paints. Thus, the modern research is moving to the development
of new bio-based paint and coatings [169].
8.4.5 Bio-based Paints and Coatings
Vegetable oils (VO) were used as the primary constituent in paints and coatings
even during the days of cave paintings. VO were used as binders or additives in
paint and coating technology for many centuries. They find numerous industrial
applications in the field, such as plasticizers, adhesives, paints and coatings [8]. VO
are non-toxic, non-depletable, non-volatile and biodegradable resources. They can
be used to produce polymers that find applications in the development of paints and
coatings. Several VO-based materials have been developed and are tailor-made for
a huge number of applications.
The primary use of VO in coatings is as drying agent, namely highly unsaturated
oils able to oligomerize or polymerize when exposed to the oxygen in air, in the
presence or absence of a catalyst. This procedure leads to an overall increase in
the molecular weight due to the crosslinking [128, 129]. Some of the common fatty
acids found in drying oils include oleic, palmitic, myristic, stearic, linoleic, linolenic,
pinolenic, ricinoleic and α-eleostearic. Therefore, only linoleic, linolenic, pinolenic,
dehydrated ricinoleic and α-eleostearic acids are truly drying oils. These VO are
R. Tesser et al.
The second solution is related to the development of new ‘compliant’ coating
technology, addresses the need for energy conservation, balances cost against necessary performance and provides compliance with environmental regulations [229].
In this case, four types of application can be possible:
• Waterborne coatings: coatings that utilize water as the major carrier liquid. The
resins commonly used need to be high hydrophilic, i.e. acrylics, alkyds, polyesters,
epoxies, polyurethanes and vinyls with common crosslinkers being melamines,
aziridines, carbodiimides and glycidyl compounds.
• Radiation curable coatings: combinations of unsaturated monofunctional and
multi-functional acrylated monomers and acrylated oligomers, characterized by
the presence of epoxy, polyester or polyurethane backbone.
• High solids coatings: incrementing the amount (>60%vol.) of solids in a conventional solvent-borne paint, it is possible to reduce the VOC content of a coating
formulation.
• Powder coatings: two types of powder coatings, thermoplastic and thermoset. The
firsts are resins melting and flowing at elevated temperatures; the seconds provide
similar melting and flow properties (75–85 °C) while changing their chemical
properties upon curing (140–200 °C).
Among the classical resins used in formations, different kinds of chemicals can be
used: i.e., acrylic, alkyd and polyesters, amino, epoxy resins and polyurethanes. Vegetable oils can be used as raw materials in producing most of the mentioned classes,
with the advantage of starting from a renewable resource, thus obtaining environmentally friendly paints. Thus, the modern research is moving to the development
of new bio-based paint and coatings [169].
8.4.5 Bio-based Paints and Coatings
Vegetable oils (VO) were used as the primary constituent in paints and coatings
even during the days of cave paintings. VO were used as binders or additives in
paint and coating technology for many centuries. They find numerous industrial
applications in the field, such as plasticizers, adhesives, paints and coatings [8]. VO
are non-toxic, non-depletable, non-volatile and biodegradable resources. They can
be used to produce polymers that find applications in the development of paints and
coatings. Several VO-based materials have been developed and are tailor-made for
a huge number of applications.
The primary use of VO in coatings is as drying agent, namely highly unsaturated
oils able to oligomerize or polymerize when exposed to the oxygen in air, in the
presence or absence of a catalyst. This procedure leads to an overall increase in
the molecular weight due to the crosslinking [128, 129]. Some of the common fatty
acids found in drying oils include oleic, palmitic, myristic, stearic, linoleic, linolenic,
pinolenic, ricinoleic and α-eleostearic. Therefore, only linoleic, linolenic, pinolenic,
dehydrated ricinoleic and α-eleostearic acids are truly drying oils. These VO are